of jamestown



No. 750,998. PATENTBD PEB. 2, 1904.

E. OHNSTRAND.

ST'AIRWAY.

APPLICATION FILED FEB.20, 1903.

N0 MODEL.

Patented February 2, 1904.

UNITED STATES PATENT OFFICE.

ENOCH OHNSTRAND, OF JAMESTOWN, NEW YORK, ASSIGNOR TO ART METAL CONSTRUCTION COMPANY, OF JAMESTOVN, NEI/V YORK, A CORPORATION OF NEW YORK.

STAIRWAY.

SPECIFICATION forming part of Letters Patent No. 750,998, dated February 2, 1904.

Application lled February 20,1903. Serial No. 144,222. (No model.)

To all whom, it may concern.:

Be it known that I, ENocH OHNsTRAND, a resident of Jamestown, in the county of Chautauqua and Stat-e of New York, have invented a new and useful Improvement in Stairways; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to spiral stairways, and more especially to metallic stairways for use in banks, vaults, libraries, or other places where a light freproof structure is desirable, the object of my invention being to provide such a metallic stairway in which the risers and treads of the stairs as well as the stringers may be formed of plate or sheet metal so formed and assembled as to reduce the number of parts and provide a light but durable staircase.

To these ends my invention comprises the novel features hereinafter set forth and claimed.

To enable others skilled in the art to make and use my invention, I will describe the same with reference to the accompanying drawings, in which- Figure l is a view of a portion of a spiral stairway embodying my invention. Fig. 2 is an enlarged perspective view of the tread and riser and the manner of securing same to the central support or pillar. Fig. 3 is a sectional View of the stringer. Fig. 4 is a sectional view of the tread and riser.

Like numerals indicate like parts in each of the figures.

In the accompanying drawings the numeral 2 designates the central column or pillar around which the stairway is wound, said pillar being supported in any suitable manner, and said pillar, if desired, may be formed of tubing of proper diameter. The steps consist of the risers 3 and treads 4, formed from one piece of sheet metal, the risers having the tongues or extensions 5,formed thereon,adapt ed to encircle the pillar 2 and secured by means of the rivets 6 or in any other suitable manner. The tongue 5 forms thus a sleeve surrounding the pillar, said tongue being riveted to the Y riser. The outer end of the riser 3 is provided sides thereof, the spring of the metal of the/ tube itself being suiiicient to hold said beading in place without the employment of other fastening means. Each tread or riser is provided with a iiange to form a connection with the adjoining riser or tread. The preferred construction is illustrated, the tread 4 of the step being provided with the flange 9 along its rear end adapted to be riveted to the riser of the next succeeding step, the downwardlyextending iange IOn at the outer end of said tread being adapted to be secured to the Stringer 8. In this manner the spiral stairway is built up, the tongues 5 of the risers of each succeeding step encircling the pillar 2, so as to rest one upon the other in the manner shown in Fig. l, while each riser and tread is secured in the manner desired to the riser of the succeeding step and to the Stringer. By my invent-ion a light but very rigid construction is thus obtained, the cost of construction and labor being reduced by the fact of the risers and treads being formed of one piece of metal and secured to each other without the use of separate connecting-pieces.

Spiral stairways constructedin accordance with my invention will be found to be particularly applicable for use in banks, vaults, and libraries, where a fireproof structure is required and where a light compact staircase is desirable. By forming the tread and riser of each step from one piece of metal no joints are formed at the outer edge of the step and a strong, stiff, and durable structure is obtained. No separate connecting device is required to connect the steps to the central col-l umn or pillar, and a neat appearance is obtained by the continuation of the riser around the pillar, While at the same time e very secure and durable connection With said pillar is made.

I/Vhat I claim is- In a spiral stairway, the combination with a suitable post, pillar or Column, of a Step having the riser and tread formed from one piece of plate or sheet metal, seid treed and riser having flanges adapted to be secured to the Stringer. IO

In testimony Whereoil I, the Sayid ENOCH OHNSTRAND, have hereunto set my hand.

ENOCH OHNSTRAND. `Witnesses:

A. GILBERT, R. M. BAUER. 

